A powerful Christmas week storm is dumping rain across Southern California, putting at-risk communities on alert for possible mudslides and creating slick driving conditions for the region as a whole.
The atmospheric river is bringing several inches of rain over the next few days, raising the risk of flash flooding and triggering evacuation warnings and orders in some areas.
Significant rain has already slammed Southern California, and the wet weather will stick around through Friday.

Los Angeles County leaders are urging residents to stay alert and heed warnings ahead of the bulk of the storm – whether they live on the coast, in the mountains or in recent burn scar areas.
The National Weather Service is warning of the excessive risk for flash flooding, as well as rock and mudslides. Evacuation warnings are in effect for several areas.
During a press conference ahead of the storm Tuesday, county leaders said that people should avoid unnecessary travel if possible.
"The last thing we want to do is ruin anybody's Christmas plans," said L.A. County Sheriff Robert Luna. "… But we have an obligation as a county family to wave the flag and say there's a threat. A real threat out there."
Meanwhile, the county is opening three emergency shelter locations for anybody who needs a safe place to go during the storm.
Evacuation warnings and orders are in place for Los Angeles County ahead of the storm, the recent burn areas like the Palisades and Eaton fire zones.
Los Angeles County officials hosted a press conference Tuesday morning, urging residents to follow any warnings and orders and to leave early if they've been told to evacuate.
"When we're talking about evacuation orders, that means that we have determined, as a team, primarily Public Works, that there's an immediate danger, or a potential immediate danger, to your safety and the safety of your family," said L.A. County Sheriff Robert Luna. "If we're talking about evacuation warnings, that's a potential warning. You need to pay attention to both."
Mark Pestrella, the director of L.A. County Public Works, said there's going to be a lot of rain over a short period of time, so many areas are being closely monitored.
"We haven't had an atmospheric event like this in some time, probably more than four or five years now," he said. "These events do produce high quantities of water … so the basin is going to attempt to drain a lot of water in a short period of time."
Pestrella said the heaviest rain is expected Tuesday night through Wednesday morning and again on Christmas Day.
"We've identified over the last year vulnerable properties … some 383 properties are considered needing evacuation," he said when discussing evacuation warnings and orders. "We also have an additional 200 orders going out to city areas."
A flood watch will be in effect from Tuesday afternoon through Thursday evening for much of the county, with mud and debris flows possible across foothill and mountain areas, including recent burn scars, according to the National Weather Service.
The city of Los Angeles issued evacuation warnings that will be in effect from 11 a.m. Tuesday through 11 p.m. Thursday for residents of Pacific Palisades and Mandeville Canyon near the Palisades Fire, and south of Runyon Canyon near the Sunset Fire area.
City News Service, Inc. contributed to this report.
If you're traveling, be sure to watch out for any delays due to weather.
More than 8 million Americans are expected to take flights Tuesday, including close to a million people flying out of Southern California airports. A storm is expected to arrive later in the afternoon and a cross- country storm is set to bring snow to the northeast, including New York City and Boston.
"We already missed our flight," said one traveler who spoke with Eyewitness News. "We arrived too late. We missed the check-in time, so we were supposed to come two hours ahead of time and we didn't at all. So we missed the cut off time to check our bags, and now I'm on hold with United to see if we can book another flight."
For others, it was a different story.
"I'll be honest, it wasn't so bad," said Rebecca Hedwat. "Honestly! We travel every year around this time, and this is probably the best for me. We left also super early."
So be sure to leave early, and that also applies to those of hitting the roads.
AAA predicts that a record 10.2 million people around Southern California will travel at least 50 miles from home during the holiday travel period.
If you factor in the heavy rain, traffic will likely be slow – so be prepared.
Rain could start falling in Southern California as early as Tuesday afternoon. It'll start off scattered and light but intensify, especially overnight, into Wednesday.
The heaviest rainfall is expected to fall on Christmas Eve, especially in the early morning. The heaviest downpours will happen during the 6 a.m. hour, with more rain in the forecast on Christmas Day.
Two to as much as 4 inches of rain is expected to fall within a 24-hour span.
The wet weather is expected to stick around through Friday, though the rain chances will begin to taper off.
The sunshine will peak through over the weekend, but only briefly. Another system brings the return of rain chances next Monday.
Check here for the latest forecast.

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